drm/msm/dsi-staging: add support for dsi dynamic clock switch

This change adds support for dynamic switching of dsi clocks
to avoid RF interference issues. Also with dynamic dsi clock
switch feature coming into picture, now populate the supported
refresh rate as list instead of providing a range. Modify the
logic to enumerate all the modes in dsi driver, taking dynamic
bit clocks, resolutions and refresh rates into account.

Change-Id: I5b6e62bc935cf2234bdd96fcb3c7537b4e735fff
Signed-off-by: Sandeep Panda <spanda@codeaurora.org>